Nanoscopic electric potential probing: Influence of probe-sample interface on spatial resolution

The apparent differences in captured scanning voltage microscopy (SVM) images on n- or p-type semiconductors were analyzed. The energy band alignment at the probe-sample interface as the source of the observed differences was identified. It was shown that spatial resolution depend on the time required for the voltage measurement circuit to reach steady state with the local electric potential of the sample. The results show that for accurate measurements, the SVM scan speed must be limited by the ratio of spatial resolution to the slowest time required to reach steady state.